Chemical interactions between Saturn's atmosphere and its rings

J H Waite Jr; R S Perryman; M E Perry; K E Miller; J Bell; T E Cravens; C R Glein; J Grimes; M Hedman; J Cuzzi; T Brockwell; B Teolis; L Moore; D G Mitchell; A Persoon; W S Kurth; J-E Wahlund; M Morooka; L Z Hadid; S Chocron; J Walker; A Nagy; R Yelle; S Ledvina; R Johnson; W Tseng; O J Tucker; W-H Ip

doi:10.1126/science.aat2382

Chemical interactions between Saturn's atmosphere and its rings

Science. 2018 Oct 5;362(6410):eaat2382. doi: 10.1126/science.aat2382. Epub 2018 Oct 4.

Authors

J H Waite Jr¹, R S Perryman², M E Perry³, K E Miller², J Bell^{4

5}, T E Cravens⁶, C R Glein², J Grimes², M Hedman⁷, J Cuzzi⁸, T Brockwell², B Teolis², L Moore⁹, D G Mitchell³, A Persoon¹⁰, W S Kurth¹⁰, J-E Wahlund¹¹, M Morooka¹¹, L Z Hadid¹¹, S Chocron², J Walker², A Nagy¹², R Yelle¹³, S Ledvina¹⁴, R Johnson¹⁵, W Tseng¹⁶, O J Tucker⁵, W-H Ip¹⁷

Affiliations

¹ Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX 78238, USA. hwaite@swri.edu.
² Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX 78238, USA.
³ Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.
⁴ National Institute of Aerospace, Hampton, VA 23666, USA.
⁵ NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
⁶ Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA.
⁷ Department of Physics, University of Idaho, Moscow, ID 83844, USA.
⁸ NASA Ames Research Center, Moffett Field, CA 94035, USA.
⁹ Center for Space Physics, Boston University, Boston, MA 02215, USA.
¹⁰ Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA.
¹¹ Swedish Institute of Space Physics, SE-751 21 Uppsala, Sweden.
¹² Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
¹³ Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.
¹⁴ Space Science Laboratory, University of California, Berkeley, CA 94720, USA.
¹⁵ Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA.
¹⁶ Department of Earth Sciences, National Taiwan Normal University, Taipei 11677, Taiwan.
¹⁷ Institutes of Astronomy and Space Science, National Central University, Chung Li 32054, Taiwan.

PMID: 30287634
DOI: 10.1126/science.aat2382

Abstract

The Pioneer and Voyager spacecraft made close-up measurements of Saturn's ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical interaction between the rings and atmosphere. Exploring this interaction provides information on ring composition and the influence on Saturn's atmosphere from infalling material. The Cassini Ion Neutral Mass Spectrometer sampled in situ the region between the D ring and Saturn during the spacecraft's Grand Finale phase. We used these measurements to characterize the atmospheric structure and material influx from the rings. The atmospheric He/H₂ ratio is 10 to 16%. Volatile compounds from the rings (methane; carbon monoxide and/or molecular nitrogen), as well as larger organic-bearing grains, are flowing inward at a rate of 4800 to 45,000 kilograms per second.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't